1. Field of the Invention
This invention relates to a label cassette retaining device for a labeler used for manually applying labels to objects.
2. Description of the Prior Art
The assignee's U.S. Pat. No. 4,436,573 teaches a configuration enabling label cassettes to be loaded into and unloaded from a labeler of this type.
The label cassette and main labeler unit combination according to this patent is designed such that when an operating lever of the main labeler unit is squeezed and released, conveyance claws provided at the bottom of the main labeler unit and engaged with the feed flaps of a backing strip having labels provisionally attached thereon are reciprocated for feeding the backing strip. The backing strip is turned back sharply near the forward end of the label cassette so that a single label is peeled off the backing strip with each reciprocation. The peeled-off label can then be applied to an object.
However, when the labeler is handled roughly, as during rapid labeling, the label cassette loaded in the main labeler unit is liable to fall out.
For preventing this problem, the prior art labeler is provided at the forward end of the main labeler unit and the label cassette with a first engagement means comprised of projections and recesses and at the rearward end thereof with second engagement means constituted as a lock mechanism.
Despite the provision of the first and second engagement means, however, the label cassette is nevertheless apt to fall out of the main labeler unit during rapid labeling operations conducted using a wide, and therefore heavy, label roll.
In addition, when labeling is continued over a long period using a wide, heavy label roll, the restraint on the label roll in the widthwise (lateral) direction tends to loosen. When this happens, the label roll not only loses it shape but also moves laterally along its spool. This may cause the labels to loosen or be damaged.